Going Up ... In Flames

When integrating building systems with fire alarm systems, we normally consider the more obvious list of building systems: heating, ventilating and air conditioning (HVAC); lighting; fire protection (sprinkler, restaurant hood suppression, etc.); security; access control; other low-voltage; and elevators.

NFPA 72-2007 labels some of these integrated systems “fire safety functions” and defines them as “building and fire control functions that are intended to increase the level of life safety for occupants or to control the spread of the harmful effects of fire.” Some of the more typical fire safety functions include elevator recall, elevator power shut down, door release, door unlocking, HVAC shutdown and smoke damper control. Other systems that are not directly related to fire safety functions simply may be monitored or integrated to operate with or through the fire alarm system.

Fire safety functions are normally performed automatically but are not allowed to interfere with the fire alarm system operation, power for lighting or power for elevators. A fire safety function control device is “the fire alarm system component that directly interfaces with the control system that controls the fire safety function.”

Contractors are aware that any listed appliance or relay connected to the fire alarm system used to initiate control of protected premises’ fire safety functions must be located within 3 feet of the controlled circuit or appliance. They also know the installation wiring between the fire alarm control unit and the relay or other appliance must be monitored for integrity. This requirement can be avoided if the fire safety function is wired in a fail-safe fashion. For example, if the fan that is to be shut down when the fire alarm system smoke detector actuates will automatically shut down if the installation wiring is cut, the system is wired in a fail-safe mode, and the installation wiring does not have to be monitored for integrity.

Elevator recall for firefighters’ service is a common fire safety function that often challenges contractors. Typically, smoke detectors are used to initiate elevator recall, and unless otherwise required by the authority having jurisdiction, only the elevator lobby, elevator hoistway and the elevator machine room smoke detectors, or other automatic fire detection as permitted by the code, will be used to recall elevators for firefighters’ service.

There are multiple ways of providing elevator recall, so the contractor should be aware of the requirements of each method. The code requires that each elevator lobby, elevator hoistway and elevator machine room smoke detector be capable of initiating elevator recall when all other devices on the same initiating device circuit have been manually or automatically placed in the alarm condition. This issue only arises when two-wire smoke detectors are used in initiating device circuits. With this type of circuit and detector, any short on the circuit will prevent the operation of the elevator recall function.

Another little-known requirement is that smoke detectors must not be installed in unsprinklered elevator hoistways unless they are installed to activate the elevator hoistway smoke relief equipment. This requirement in NFPA 72-2007 is to prevent false alarms from occurring from a detector that rarely receives service, and since NFPA 13 does not require new elevator shafts to be protected by a sprinkler, contractors should almost never be required to install a smoke detector in the hoistway.

Also, the contractor is allowed to program smoke detectors mounted in the air ducts of HVAC systems to initiate either an alarm signal at the protected premises or a supervisory signal at a constantly attended location or supervising station.

In many building security situations, door-unlocking devices will be employed. The code requires that any device or system intended to actuate the locking or unlocking of exits be connected to the fire alarm system serving the protected premises. All exit door locks connected in this fashion must unlock upon receipt of any fire alarm signal by means of the fire alarm system serving the protected premises.

Integrating building systems with fire alarm systems can be challenging, so it is important to know what is expected of the integrated operation and how to properly install these systems. Obtain “Building Automation Control Devices and Applications,” the recently published book by the National Joint Apprenticeship and Training Committee for the Electrical Industry and American Technical Publishers Inc. It will provide a foundation for you to understand the common applications of control devices and the integration of multiple building systems into sophisticated building automation systems.

Owners of new buildings will continue to look for savings in both the use and operation of building systems. Some of these savings will be from the integration of the various systems to provide more efficient operation. If you become knowledgeable in the use and installation of these systems, your business will grow with the market.

MOORE, a licensed fire protection engineer, frequent speaker and an expert in the life safety field, is a co-editor of the current National Fire Alarm Code Handbook. Moore is a principal with Hughes Associates Inc. at the Warwick, R.I., office.